/**
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
 * agreements.  See the NOTICE file distributed with this work for additional information regarding
 * copyright ownership.  The ASF licenses this file to you under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with the License.  You may obtain
 * a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package org.apache.zookeeper.server.util;

public class ZxidUtils {
    static public long getEpochFromZxid(long zxid) {
        return zxid >> 32L;
    }

    static public long getCounterFromZxid(long zxid) {
        return zxid & 0xffffffffL;
    }

    /**
     * 根据Leader Epoch，计算出zxid
     * 在这里就体现出zxid的高32位为Epoch。
     *
     * @param epoch
     * @param counter
     * @return
     */
    static public long makeZxid(long epoch, long counter) {
        return (epoch << 32L) | (counter & 0xffffffffL);
    }

    static public String zxidToString(long zxid) {
        return Long.toHexString(zxid);
    }
}
